Underground and submersible junction bus connectors are widely used in electrical power distribution systems. One type of such connector is offered under the designation SWEETHEART® by Thomas & Betts International, Inc. of Memphis, Tenn., the assignee of the present invention. The SWEETHEART® connector is a cast or welded aluminum connector including a bus, or bar, portion and a series of tubular posts extending outwardly from the bus portion. The posts have an open upper end to receive one or more electrical conductors. A threaded bore is provided in the sidewall of the post, and which receives a fastener to secure the electrical conductor within the upper end of the post. An insulating coating is provided on the lower portion of the posts and bus of the connector. In addition, EPDM insulating sleeves may be used to provide waterproof seals for the posts. U.S. Pat. Nos. 6,347,966; 6,345,438 and 6,263,567 disclose various embodiments of such bus and post connectors.
Thomas & Betts also manufacturers a RAB series of “Flood Seal”® Rubberized Aluminum Bar connectors suitable for direct burial, handhole or pedestal applications. The RAB connector includes a generally rectangular aluminum body having a plurality of spaced apart cable-receiving passageways therein. As the name states, the RAB connector includes a rubber insulating cover over the connector body. The insulating cover includes integrally molded inlets for both the cable-receiving openings and fastener-receiving openings. An insulating boot, such as a cable size adaptor or Rocket may be provided for the cable-receiving inlet, and a sealing cap may be received over the screw in the fastener-receiving inlet.
U.S. Pat. No. 6,688,921 to Borgstrom et al. discloses a connector similar to the Thomas & Betts RAB series connector. In place of EPDM, the patent uses a thermoplastic elastomer (TPE) that combines the properties of thermoplastic with the performance characteristics of a thermoset rubber. The use of TPE enables the molding to further form sealing plugs attached to the cover with respective tethers. A cable size adaptor is frangibly connected to each sealing plug via an integrally molded web.
Michaud Electrical Equipment of France offered an insulation displacing connector (IDC) including a generally rectangular connector body, and transverse cable-receiving and fastener-receiving passageways. More particularly, the connector body included a backwall having a pattern of sharp ridges thereon to pierce the insulation on the cable end as the end of the fastener engages and presses against the cable end from the opposite side. To be sure the cable end is fully pressed onto the sharp ridges, a plastic viewing window is provided opposite the inlet of the cable-receiving passageway. Accordingly, an installer can view the cable end to be sure the insulation has been pierced. The window is adjacent the rubber cover. Unfortunately, the Michaud IDC device is likely to leak at the window since the seal is only a mechanical seal. In addition, insulation displacement technology may not be suitable for larger cable sizes with thicker insulation coverings.
A significant advance in the area of connectors is disclosed in U.S. Pat. No. 7,144,279, assigned to Thomas & Betts International, Inc., the assignee of the present invention. The connector includes an electrically conductive body, a thermoplastic elastomer (TPE) insulating cover, and windows aligned with cable end viewing openings in the conductive body. The electrically conductive body has spaced apart cable-receiving passageways for receiving respective electrical cable ends therein, and with each cable-receiving passageway having a cable inlet opening and a cable end viewing opening opposite the cable inlet opening. The electrically conductive body also has a respective fastener-receiving passageway intersecting each of the cable-receiving passageways. The windows provide a cover and permit visual confirmation of proper placement of the electrical cable end within a corresponding one of the cable-receiving passageways. The electrical connector also includes a respective removable fastener inlet closure cap for each tubular fastener inlet, and a respective flexible tether having a proximal end removably connected adjacent a corresponding tubular fastener inlet and a distal end integrally molded with a corresponding removable fastener inlet closure cap. A respective insulating boot may be received in each of the tubular cable inlets. Each insulating boot may include a tubular sidewall having a progressively increasing diameter to an open outer end thereof, a removable boot closure cap for removable positioning in the open outer end of the tubular sidewall, and an integrally molded tether connecting the removable boot closure cap to the tubular sidewall.
U.S. Pat. No. 7,160,146 to Cawood et al., and assigned to the assignee of the present application, discloses an insulating boot associated with the conductor receiving passageway of an electrical connector. The insulating boot may include an insulating tube, and at least one rupturable seal closing the insulating tube and rupturing upon initial insertion of the cable end therethrough. The rupturable seal may also be compliant to accommodate different sized cable ends and form a seal with adjacent portions of the cable end. A pair of seals may be provided with an optional sealant material therebetween.
A number of attempts have been made to provide environmental cable end seals for the connectors of the type described above, in particular, to accommodate various size wires and cables that may be advantageously used with such connectors. Unfortunately, such seals have not always provided proper sealing or accommodated sufficiently differently sized wires and cables.